You depend on the water coming from your taps to be clear and clean. What if the water suddenly tastes off or the color has changed? This could be a sign of rust. Depending on the age of the pipes in your home and water heater, it could be coming from inside your house. There is a chance that rusty water could stem from your public supply, especially if you live in an older city that hasn’t refurbished its water system in several decades. However, you can follow a few clues that point to the source.
Finding the Source of Rusty Water
Often it doesn’t take a lab test to determine of the impurity in a water sample is rust. Rusty water will have a distinctive metallic odor and a reddish-brown 
appearance. Rust particles are oxidized iron. While this may leave unsightly stains in porcelain sinks and white linens, it doesn’t pose a health hazard. One exception would be those with hemochromatosis. This is a rare disorder that allows the body to accumulate excessive iron levels.
So where is the rust coming from? First you have to determine if the rusty water is originating within your home system or in the public supply. To investigate, go to the fixtures where you first noticed the rusty water and fill a glass with cold water only. Check it for any odors or coloring. Let the cold-water flow for several seconds before checking another sample. Once that is done, run the hot water for several second and sample that.
If the rust is only present in the hot water, or if it goes away after several seconds of running water, those are strong indications that the rust source is in your home. However, If you have continuous rusty water in both taps, you should call your local water authority to report the problem. This test should help you further narrow down the source if you find it is within your home. If rusty water came from the cold-water tap, that indicates a corroding pipe or pipes in your plumbing system. If it is only coming from the hot water tap, this means your water heater is likely rusting out.
